1. Field of Invention
The present invention generally relates to network communication systems, and more particularly, to systems and methods for performing service-based compression of content within a network communication system.
2. Description of Related Art
The increasing deployment of Internet-based architectures, such as TCP/IP, within modern communication systems has exposed many of the limitations associated with a single, ubiquitous design. Because the Internet was initially intended to provide a free network in which stationary hosts predominately send unicast, reliable, sequenced, non-real-time data streams, the Internet was designed to be robust and minimalistic, with much of the functionality provided by the end hosts. The Internet, however, is increasingly required to support very diverse environments (heterogeneous wireline/wireless networks), applications (email, multimedia, WWW) and workloads (heterogeneous unicast and multicast streams with different quality of service requirements). The problem with supporting such diversity with a single network architecture is that different applications may have very different and potentially incompatible requirements.
Supporting applications that employ physical channels with significantly different signaling characteristics has proven especially problematic. In heterogeneous wireless/wireline networks, for example, the wireless channels are typically characterized by a relatively low bandwidth and a relatively high occurrence of random packet loss and deep fades. Because conventional Internet-based architectures typically assume that physical channels have a relatively high bandwidth and a relatively low occurrence of random packet loss, these architectures may erroneously conclude that packet loss was caused by congestion, rather than a temporary degradation in the signal quality of the wireless channel. For systems employing a TCP/IP architecture, this erroneous detection of congestion loss may cause the server to significantly decrease the rate at which data is transmitted to the wireless client, resulting in under-utilization of the limited bandwidth resources of the wireless channel. As a result, heterogeneous wireless/wireline networks typically exhibit sub-optimal performance and typically provide inefficient or ineffective use of limited wireless bandwidth resources.
These problems have become increasingly apparent with the increased popularity of wireless transmission of email messages, which often include large and uncompressed attachments. The transmission of large uncompressed files over a low bandwidth wireless channel not only results in an inefficient use of limited resources, but also increases the probability of random packet loss (and associated throttling of transmission rates) during transmission of the email message. Although many of these problems could be alleviated if users would compress email attachments before they are sent, most users are either unwilling or unable to do so. Many users may also be reluctant to compress email attachments because the user may be uncertain as to whether the recipient will have the appropriate software to decompress the attachments. Consequently, most email messages are transmitted over a wireless channel in an uncompressed format, which results in an inefficient use of wireless bandwidth, an increased probability of error or random packet loss during transmission and potentially significant download times.
Therefore, in light of deficiencies of existing network architectures, there is a need for improved systems and methods for performing service-based compression of content, such as email messages, within a network communications system. There also is a need to provide such systems and methods in a manner transparent to the client and server so as to avoid requiring the server to perform special processing on the content before the content is transmitted to the client and to avoid requiring the client to install and configure special decompression software to support the service-based compression.